HTML

<div class="col one">
This example showcases use of (fake) vw unit. While things like width were already easy to tie to width of viewport, other properties, such as padding or font size or border radius were not. You should be able to see a couple of boxes with text, which are supposed to change font size, border width, border radius, and padding in response to viewport width changes.
</div>
<div class="col two">
This example showcases use of (fake) vw unit. While things like width were already easy to tie to width of viewport, other properties, such as padding or font size or border radius were not. You should be able to see a couple of boxes with text, which are supposed to change font size, border width, border radius, and padding in response to viewport width changes.
</div>
<div class="col three">
This column does not use the viewport width scaling, and so does not change (except in width) when the window is resized or device is rotated.
</div>

Misc

We're all for progressive enhancement, but CodePen is a bit unique in that it's all about writing and showing front end code, including JavaScript. It's required to use most of the features of CodePen.